[Server-devel] Congratulations - Some questions

Martin Langhoff martin.langhoff at gmail.com
Sat Oct 10 08:37:56 EDT 2009

On Sat, Oct 10, 2009 at 8:08 AM, Rangan Srikhanta <rangan at laptop.org.au> wrote:
> Congratulations. This is remarkable step forward and I am pleased to see the


> -          Reliability of presence (only noted with four XOs, but a thorough
> 100+ XO test is likely to occur on Monday)

Wow! Good. If you are going to use 100+ machines I would recommend...

 - many APs, say around one for every 30...

 - careful planning (and testing) of how to set the channels on each,
always using using 1,6 and 11

 - use Moodle to control presence -- see in the 'techniques' page in
the wiki how to do it...

> We will be rolling out over 500 XO laptops across six deployment sites in
> the next couple of months. I am thinking that rolling out the XS in some
> form may be an option for one of the states we are rolling out to.

Well, that means that you'll have ~100 XOs per deployment. You
definitely want to have an XS.

> Some questions (sorry if they seem silly, I’ve lost track of the XS
> development process):
> -          How many XOs can be connected to an XS? 60, 120, 250?

A single XS will handle that and a lot more. A high end desktop /
low-end "SOHO" server should handle to the tune of 500 users just
fine. Just give the XS plenty of RAM (4GB! :-) ) and more diskspace
(2GB diskspace under /library per XO recommended).

> -          What is the deal with XOs to AP ratios, we are using WRT54GLs, is
> it 20 XOs per AP? Or is it potentially much more.

I always forget which APs place caps on the numbers of associated
nodes (just get one that doesn't ;-) ). As long as the AP can handle
the number of associated nodes, the "sane" recommendation is between
20 and 40 (or even more) but it depends on the usage.

Also, school layout and building materials will determine your
antenna/AP placement strategies.

> -          Some issues with changing the Administrator name as well as XO

Don't know about that :-) if you trick the machine to be de-registered
and re-register it, Moodle will probably pick up the change.


 martin.langhoff at gmail.com
 martin at laptop.org -- School Server Architect
 - ask interesting questions
 - don't get distracted with shiny stuff  - working code first
 - http://wiki.laptop.org/go/User:Martinlanghoff

More information about the Server-devel mailing list